HOW TO ESTIMATE THE AMOUNT OF WIRE TO WIRE A NEW BUILDING

Good morning all,i am to estimate the amount of wire to use to wire a 4 bedroom flat.how do i estimate the total lenght of wire for live,neutral,and earth for the ring circuit.And that of AC circuit.
please any rough method of calculation?
please do help a brother.
thanks.
ovis

Take your plan
Work out where you want the electrical accessories
Work out how the cable will be routed between them (making sure you are aware of the local rules for routing cables whatever they may be)
Add up the lengths.
Add some more on to allow for unanticipated routing issues.